Brain Higher Functions Diencephalon Cerebellum Cerebral Hemispheres Cerebral
Brain Higher Functions • Diencephalon • Cerebellum • Cerebral Hemispheres Cerebral hemispheres Cerebellum “ 2 -oval skull” (includes regions of higher functions) 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Diencephalon (integrates conscious and unconscious activity) • Between cerebral hemispheres • Mostly thalamus and hypothalamus 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Thalamus Diencephalon (relays sensory information and emotional state) • Five groups of nuclei 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions – Anterior group—limbic system – Medial group—hypothalamus emotion center to cerebrum frontal lobe – Ventral group—touch and proprioceptive information relayed to cerebral cortex – Posterior group—optic and auditory information to cerebral cortex – Lateral group—emotional state feedback from limbic system; integrates with sensory information
Limbic system 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions Diencephalon
Limbic system 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions Diencephalon
Hypothalamus Diencephalon • Superior to pituitary gland (gland is in sella turcica) • Connected to pituitary by infundibulum stalk 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Diencephalon Hypothalamus function • Feeding reflexes—licking, swallowing, etc. • Subconscious skeletal muscle movements—facial expressions, sexual movements • Autonomic center—control medulla oblongata nuclei for cardiovascular, respiration • Secretes oxytocin that stimulates smooth muscle of uterus, mammary glands and prostate • Regulates body temperature • Controls pituitary gland by hormonal secretion—pituitary in turn regulates many hormonal endocrine functions • Produces emotions/sensations/drives: e. g. thirst, hunger (not really “sensations” from periphery) • Coordinates autonomic response to conscious input— 12/4/2020 thought of fear produces accelerated heart rate, etc. Human Anatomy and Physiology I, Frolich, Higher Brain Functions
12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Pineal gland • Regulates Cycles • Secretes melatonin which helps regulate circadian and reproductive cycles 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions Diencephalon
Cerebellum (posture and movement) • Oval at back of cranial cavity • Convoluted surface of neural cortex (like cerebrum) • Huge branching Purkinje cells —each cell gets input from 200, 000 synapses • Internal branching looks like tree—called “arbor vitae (tree of life) • Damage leads to “ataxia”— disturbance of muscular coordination 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Cerebrum (processing central for somatic/conscious information) • Two cerebral hemispheres separated by longitudinal fissure (sagittal plane) • Central sulcus divide (coronal plane) separates frontal lobe from parietal lobe • Horizontal lateral sulcus (in transverse plane) separates frontal lobe from temporal lobe • Parietal-occipital sulculs separates parietal lobe from occipital lobe 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Cerebrum overall organization • Left side receives somatic sensory and controls somatic motor of right side of body (and vice versa) • Two hemispheres have different specialized areas (not symmetrical) • Correspondence of functions with regions is difficult—lots of overlap and ability to “fill in” if areas are damaged • Corpus callosum is bundle of 12/4/2020 axons that link two sides Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Cerebrum 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Cerebrum Cerebral function in brief • Basal nuclei – Deep in hemispheres – Subconscious control of skeletal muscle – Rhythmic movements—overall walking coordination • Frontal Lobe (primary motor cortex)-voluntary control of skeletal muscle • Parietal lobe (primary sensory cortex)—conscious perception from skin—touch, pressure, pain • Occipital lobe (visual cortex)—conscious perception of visual field • Temporal lobe (auditory cortex and olfactory cortex)— conscious perception of sound and smell • All Lobes—integration and processing of sensory input to initiate conscious motor output 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Cerebrum 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
Interactive overview of basic regions of brain from PBS [link] 12/4/2020 Human Anatomy and Physiology I, Frolich, Higher Brain Functions
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